Azo compounds from 1-n-morpholino-2-nitro propane



trite.

are theiipoured at once into a solution of 1m- Patented June 28, 1949 2,474,780 Azo ccMroUNns' FROM I N-MOHPHOLINO- Z- NITRO PROPANE Edward Fqlllegering, La Fayette; 1nd,, and Gerhard van Bierna, J acksonHe'ights, N. Y;., assignoi's to Purdue Research Foundation, La Fayette, Ind., a corporation of Indiana N-o Drawing. Application August 17, 1945, Serial No. 611,264

GClaims.

1 Thisinvention relates to new nitrba'zo compounds and to a method for preparing them.

More particularly it relates to ni't'roazo compounds having the following general formula.

on, Ar-N=N+C-NOQ lHz \CHPCQQ wherein Ar represents an aryl substituent group including nuclear substituted aryl groups and aryl azo aryl groups.

"stituted and including also azoarylamines, in acid or basic solution to yield colored solid compounds suitable for coloring silk, wool, and in some cases cotton and rayon. The l-N-morpholino-"2- nitropropane employed as a coupling component in our process can be prepared as described in the Master's Thesis of Robert Edward Meeker,

dated August 1942 entitled Condensation Reactions of Amines, Formaldehyde and Nitroparaffins, Purdue University, La Fayette, Ind.

While the coupling process of our inventionmay be carried out under both acid and basic conditions, we prefer to utilize an acid medimnsince decomposition tends to occur when basic conditions prevail, such decompositions often occurring with considerable violence. we prefer to utilize relatively strong acid solutions preferably solutions having a pH below about 4.

According to our present invention the approise thereto an aqueous solutionof sodium in- Theorem um chlorides thus produced Examples of compounds in i eluded within the scope of the above generic For this reason temperatures.

2 morpholino"Z-nitropropane containing an acid such as hydrochloric preferably with constant mechanical stirring. In most couplings the color develops after a few minutes of stirring at room In some instances, however, it may be necessary to employ mild heating to accelerate the coupling, for example by the use of a steam bath. The coupled nitroazo' compound may precipitate as asolid, or may remain in solution if it contains solubilizing groups as does the sulfanilic acid compound. The nitroparts of I-N morpholino-2-rritropropane iri*10 parts of concentrated hydrochloric acid (sp. g. 1.19), and 30 parts of water was subsequently poured in with continuous stirring. The solution turned first yellow, then orange, and after a few minutes a light orange precipitate was formed which was filtered off after ten minutes of stirring. The crude product, after drying in a vacuum desiccator over" anhydrous potassium carbonate, corresponding to 2 parts by weight. Recrystallization three times from 30% ethanol yielded about 1.2parts of yellow crystals melting at 125.5 C. (corr; 127.6" C.)

Analyses for nitrogen: 20.1%, 20.1%.

Theoretical amount of nitrogen: 20.15%.

Yield: 22% of theory.

EXAMFLE II Preparation of 1#N-morpholino-Z-nitro-Z-(pnaphthylazo) -propcme A quantity of 3.6 parts by weight of B-=naphthyl amine was dissolved in 15 parts of concentrated water. A solution of 1.8 8 parts of sodium nitrite inabout 30 parts of water was then added from a dropping funnel with constant" stirring. After the addition, stirring was continued for ten more priate arylaiiiine is diaz'otized in the usual way, forexar'ripleby first dissolving the arylamine in cid such ashydrochloric, and thenadding dropminutes. The diazoti'zed solution was ffilter ed, anda previously prepared solution of 435 parts of 1-N-morpholino-2-nitropropane in 10 parts of concentrated hydrochloric acid (sp'. g. 1.19) and 30 parts of water was added to it with stirring. The solution turned a deep redimmediately and after heating gently to about 35 C. a red- 7 orange precipitate formed which tended to float EXAMPLE III Preparation of 1-N-morphoZino-Z-nitro-Z-(2- carbory-pherryiazo) -propane A quantity of 3.42 parts of anthranilic acid was suspended in parts of concentrated hydrochloric acid (sp. g. 1.19) and parts of water. A solution of 1.88 parts of sodium nitrite in about parts of water was then added from a dropping funnel with constant stirring. After all of the suspended material had gone into solution stirring was continued for ten more minutes. A previously prepared solution of 4.35 parts of 1-N-morpholino-2-nitropropane in lil 'parts of concentrated hydrochloric acid (sp. g. 1.19) and 30 parts of water was subsequently poured in with continuous stirring. Upon slight heating of the reaction mixture on the steam cone the solution turned yellow and a dark yellow precipitate appeared. Upon filtering and drying in a vacuum desiccator over potassium carbonate the crude product corresponded to about 2 parts. It was purified by recrystallization from 500 parts of 50% ethanol. The yellow, crystalline product thus obtainedamounted to 1 part and had a melting point of 168.5 C. A second recrystallization carried out in an identical manner yielded to 0.5 part of fine gold plates melting at 168.5 C. (corr. 172.5 0.).

Analyses for nitrogen: 11.8%, 12.1%

Theoretical amount of nitrogen: 17.4%.

Yield: 13% of theory.

* EXAMPLE IV Preparation of 1-N-morphoZino-2-nitro-2-(4- carbomy-phenylazo) -propane A quantity of 3.42 parts of p-aminobenzoic acid was suspended in 15 parts of concentrated hydrochloric acid (sp. g. 1.19) and 20 parts of water. A solution of 1.88 parts of sodium nitrite in about 30 parts of water was then added from a dropping funnel with constant stirring. The stirring was continued for ten minutes after all of the suspended material had gone into solution. The diazotized solution was poured with continuous agitation into a suspension of about 70 parts of ice in 125 parts of a 2 N solution of sodium hydroxide.

A quantity of 4.35 parts of l-N-morpholino- Z-nitro-propane was added to a solution of 1 part of sodium hydroxide in about 30 parts of water and the resulting suspension was heated until all of the nitroamine had gone into solution. The solution was cooled to room temperature in an ice bath, and then poured into the basic diazotized solution with stirring. The reaction mixture turned a deep red immediately. When, after ten minutes of stirring, it was acidified with concentrated hydrochloric acid a heavy yellow precipitate appeared. The latter was filtered EXAMPLE V Preparation of 1-N-morpholino-Z-nitro-Z-(4- chlorophenylazo) -propane A quantity of 3.18 parts of p-chloroaniline was dissolved in 15 parts of concentrated hydrochloric acid (sp. g. 1.19) and 20 parts of water.

A solution of 1.88 parts of sodium nitrite in about 30 parts of water was then added from a dropping funnel with constant stirring. Stirring was continued for ten more minutes after the addition. A previously prepared solution of 4.35 parts of 1-N-morpholino-2-nitropropane in 10 parts of concentrated hydrochloric acid (sp. g. 1.19) and 30 parts of water was subsequently poured in with constant stirring. The solution turned yellow, then orange and a bright orange solid was formed which was recovered from the solution by filtration. The product was dried over anhydrous potassium carbonate in a vacuum desiccator and recrystallized from 200 parts of 30% ethanol, yielding 2 parts of bright orange needles melting at 1245 C. (corr. 126.8 C).

Analyses for nitrogen: 17.6%, 17.6%.

Theoretical amount of nitrogen: 17.9%.

Yield: 26% of theory.

EXAMPLE VI Preparation of I-N-morpholino-Z-nitro- 2- (Z-nitrophenylazo) -propcme A quantity of 3.6v parts of o-nitroaniline was dissolved in 15 parts of concentrated hydrochloric acid (sp. g. 1.19) and 20 parts of water. A solution of 1.88 parts of sodium nitrite in about 30 parts of water was then added from a dropping funnel with constant stirring. Stirring was continued for ten more minutes after the addition. A previously prepared solution of"4.35 parts of 1-N-morpholino-2-nitropropane in 10 parts of concentrated hydrochloric acid (sp. g. 1.19) and 39 parts water was subsequently poured in with continued stirring. The solution soon turned yellow, then orange, and finally a bright orange solid was formed which was separated from the solution by filtration. After drying over anhydrous potassium carbonate in a vacuum desiccator the crude product amounted to about 3 parts. It was purified by recrystallization from 100 parts of ethanol, yielding 2.5 parts of bright orange needles which melted at 116 C. A second and third recrystallization carried out in an identical manner gave 2.5 and 1.8 parts respectively, of orange needles melting at 116 C. (corr. 117.8 C).

Analyses for nitrogen: 21.6%, 209%.

Theoretical amount of nitrogen: 21.6%.

Yield: 32% of theory.

EXAMPLE VII Preparation of 1-N-morpholino-2-nitro- 2- (3-nitrophenylazo) -propane A quantity of 3.5 parts of n-nitroaniline was dissolved in 15 parts of concentrated hydrochloric acid (sp. g. 1.19) and 20 parts of water. A solution of 1.88 parts of sodium nitrite in about 30 parts of water was then added from a drop- "tion of 4.35'parts or 1 N rnor pr'opahe' parts of"coi icentralted= hydrochloric 1 a i rt zso tion was ccmpieteq. "A

} nu y preparei stinaci d (fSIL g.

1.19) and 30 parts of water was subsequent cured winto he diazotized solution .uous stirring.- The solution turned yellow immediately, and ayellow precipitate apts dissolved in iapti s r tcncenttateu hydro- -chlor1cacid (sp. g. 1:1

and 20 parts'oi water.

sciuticn ori-tapart or sodium nittite i-n about 30 parts or water =was*tl ienaddedfrdm a dropping funnel with constant tirriii'g. After the addition, stirrifig*was-' continued tor ten more minutes. The diazotized soliitio'r-rwassl'igh'tly turbid. A previouslyprepared solution of 4.35 parts of 1-N-morpholi no-Z-nitropropane in 10 peared. After stirring for twenty" more minutes 10 parts of concentrated hydrochloric acid (sp. g. this precipitate was filtered'off, driedina vacuum 1.19) and 30 parts of" water was then added with desiccator over anhydrous potassium carbon'ate stirring. The solutlon turned yellow, then and weighed. The crude yellow powder amounted orange, and finally an orange precipitate apto 3.5 parts. "Two successive rec'rys'tallizations peared. After tenmore minutes of stirring this from 400 parts of 25% ethanol yielded 3:2'and 3 precipitate was collected on a filter, dried over l partsrespectively, of yellow; shi'ny plates nieltanhydrous potassiuttncarbonatein a vacuum ring at:127.5 C. (corr. 129;6"G.)'. desiccator and"w'eig hed. The crud'e product Analyses for nitrogen: 21.2%, 21.4%. corresponded to 5 parts. Recrystallization Theoretical amount-ti 'riitrogen: 21.6%. from 300 parts of 40% ethanol gave4{partsof Yield: 41% of theory. 1 orangeneedles-melting at'91;5 C. "Asecond recrystallization yielded a product with identical EXAMPLE VIII 1 it prcperties- (Memng pcintccrrectedtceac 0.) Preparation of I-N-morPholz'no-Z-nitro-2- Analyses for nitrogen; 15.5%, 15.7

( p nulazo) propane rnecretic'ar percent rii'trog'ri-r 16.1%.

A quantity of 3.5 parts of p-nitroaniline was Yield: dissolved in 15 parts of concentrated hydrochloric acid (sp. g. 1.19) and 20 parts of water. EXAMPLE X A solution of 1.88 parts of sodium nitrite in about parts of water was then added from a drop- 30 Prepa a on f '1 ping funnel with constant stirring. After the p flil' d i ll -1 p addition stirring was continued for ten more minutes. A slight yellow precipitate was ob- A quantity of 4.92 parts of p-aminoazobenzene served after the diazotization. A previously prewas dissolved 15 parts of concentrated hydropared solution of 4.35 parts of l-N-morpholinochloric acid (sp. g. 1.19) and 20 parts of water. 2-nitropropane in ten parts of concentrated hy- Asolution of 1.88 parts of sodium nitrate in about drochloric acid (sp. g. 1.19) and 30 parts of water 30 parts of water was then added from a dropping was then added with stirring. A heavy yellow funnel with constant stirring. After the addition precipitate appeared almost immediately, and. stirring was continued for ten more minutes. A after the solution had been stirred for an addi- 0 previously prepared solution of 4.35 parts of 1- tional ten minutes this precipitate was isolated N-morpholino-2-nitr0propane in 10 parts of cony filtration. I wa dried v an yd us potascentrated hydrochloric acid (Sp. g. 1.19) was subsium carbonate in a vacuum desiccator. The sequently poured in with continued stirring. A crude product o sponded to about 6 parts. It brown precipitate was obtained which upon filterwas purified by recrystallization from 300 parts 45 ing and drying corresponded to about 8 parts. of ethanol, yielding 3.6 parts of golden Four successive recrystallizations of one-fourth needles with a melting point of 145 C. A second of the original precipitate from 80% ethanol recrystallization resulted in golden plates also yielded finally ,3 part of a. light brown powder l n at 0- rn 1 0- melting at 163 c. (corr. 166.8 0.).

y o nitrogen: 26.0%, 25.9%. 50 Analyses for nitrogen: 22.2%, 22.4%.

Theoretical per n o e Theoretical amount of nitrogen: 22.0%.

Yleldi of r Yield: About of theory.

EXAMPLE IX The compounds prepared according to the procedures described in the foregoing examples are P gg zgl g g gzgzggg jggi; ji 55 shown in the table below in which the appearance and physical characteristics as well as the dyeing A quantity of 4.05 parts of 2,4-dichloroaniline properties of the compounds are listed.

TABLE I Arylamines coupled with I-N-morpholino-Z- nitropropane Appearance of Azoll l i Per CentN Per Cent N Approximate W 10 l Amme Dmzotlzed Compound Product, 0. Theory Found g- 3 er o tain e d b t iittfiit taaiii: iififlt lais i'ii ijii: i251? i915? iii 5% Stfiititti: 833531.... Anthranlhc Acid 172.5 17.40 12.00 13 Yellow Yellow p-Aminobenzoic Acid. 198.4 17.40 17.2 26 Yellow-orange Yellow orange. p-Chloroanfline 126. 8 17. 17. 6 Ow O-NliEIOEIlllllElG Orange Needles 117.8 21.65 21.3 Beige. m-Nitroamlme Yellow Crystals 129.6 21.65 21.3 Y ll p-Nitroaniline Yellow Needles 147.9 21.65 26.0 O1ang9 2,4-D1ch1oroamlme Orange Needles 92.6 16.13 15.6 D() p-Aminoazobenzene" Lt. Brown Powder..- 166. 8 22.0 22.3

While the above describes the preferred embodiments of our invention, it will be understood that departures may be made therefrom within the scope of the specification and claims.

What is claimed is:

1. Nitroazo compounds having the following structural formula OHS CHFCHB om-cin wherein Ar represents an aryl substituent group being the residue of a diazotized aryl amine.

2. 1-N-rnorpholino-2-nitro 2-(3-nitrophenylazo) -p-ropane.

3. 1-N-morpho1ino-2- nitro 2 (ZA-dichlorophenylazo) -propane.

4. l-N-morpholino-Z-nitro -2 4 -phenylazophenylazo) -propane.

5. A process for preparing nitroazo compounds having the following general formula:

8 wherein Ar represents an aryl substituent group, which comprises coupling l-N-morpholino-Z-nitropropane with a diazotized aryl amine.

6. The process according to claim 5 in which the reaction is carried out in an acid solution having a pH below 4.

- EDWARD F. DEGERING.

GERHARD VAN BIEMA.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,057,455 Stenger Oct. 13, 1936 2,392,611 Nygaard Jan. 8, 1946 OTHER REFERENCES Feasley et al. in Journ. of Organic Chemistry 1943, vol. 8, pages 12-16, (Copy in Patent Ofiice Library.) 

